How Exercise Can Make You Happy (in Just 20 Minutes!)

It turns out that stressing the body by working out de-stresses the mind. We tested the effect on four sedentary women who were feeling frazzled, and the proof is in: mood-boosting, life-changing results.

Woman A is having a bad day. First, her boss comes by and barks at her for missing a deadline. Then her mom calls and guilt-trips her for forgetting her aunt’s birthday. Oh, and that new guy she has been texting? He’s MIA.

Her stress hormones—cortisol and adrenaline—are surging. In her brain, cortisol is binding with receptors in the hippocampus, the seat of memory formation and learning. For now, this will hone her recall. But if she doesn’t get her stress in check, over time, key connections between nerve cells in her brain won’t function as well, impairing her memory and her ability to take in new information, and raising her risk for depression and anxiety.

All she knows is that she’s overwhelmed. So at lunch, she heads to the gym and hops onto the elliptical. As her heart begins to pound, levels of the feel-good neurochemicals serotonin, dopamine and norepinephrine rise in her body. So does brain-derived neurotrophic factor (BDNF), a substance that may protect her brain from emotional disorders and repair damage that stress and depression cause. At the same time, opiate-like endorphins and endocannabinoids (similar to the other kind of cannabis) flood her system, leading to a sense of well-being.

People often throw around terms like “endorphin rush” or “runner’s high” to explain the mood lift that can occur during or after a sweat session. But rather than a sudden burst of euphoria, research has found that a mere 20-minute workout can produce more subtle mood benefits that last as long as 12 hours. And when it comes to shorter bouts of activity, endorphins may actually have little to do with the mental perk-up. “When researchers blocked endorphins from runners’ brains, some still said their mood improved after their workout,” says John Ratey, M.D., author of Spark: The Revolutionary New Science of Exercise and the Brain.

In part, the happiness effect may be due to endocannabinoids and BDNF; the latter may rise during exercise, prompting neural growth and repairing damage caused by ongoing stress and depression. “BDNF,” Dr. Ratey says, “is like Miracle-Gro for your brain.” When French researchers bred mice without cannabinoid receptors, the mice ran 30 to 40 percent less than normal mice, presumably because it wasn’t as pleasurable for them.

Unlike those deprived mice, Woman A is feeling so good that she cranks up the elliptical. As she does, her body begins releasing gamma-aminobutyric acid, or GABA, a calming neurotransmitter. Not that she is calm, exactly; she’s subjecting her system to a low-level form of stress. “Exercise raises your heart rate and triggers a surge of hormonal changes. Expose yourself to this ‘stress’ enough and your body builds up immunity to it. Eventually, it will get better at handling the rest of life’s stressors,” says clinical psychologist Jasper Smits, Ph.D., coauthor of Exercise for Mood and Anxiety. But stay sedentary and your body can become more sensitive to stress, so even minor triggers leave you tied up in knots.

Which leads us to Woman B. She is also having a bad morning and feeling overwhelmed. Except in her hormonally revved-up state (adrenaline! cortisol!), she decides she is too time-pressed and anxious to work out. Instead, she treats herself to a cookie and a latte. Half an hour later, the sugar and caffeine hit, sending another jolt of cortisol and adrenaline through her body. But her buzz won’t last for long. By midafternoon, she crashes and feels more stressed than before.

Over time, this kind of chronic stress can erode connections between neurons, leading to a communication breakdown in brain cells. That may partly explain why depressed and anxious people get locked into a negative mind-set. “They lose flexibility and have trouble thinking their way out of a mental rut,” Dr. Ratey says.

Not so, Woman A. After her workout, she has a sunnier outlook. Stressed or sunny? Which would you rather be?

We thought so. With those benefits in mind, SELF did an experiment. We recruited four women in the New York metropolitan area who were feeling one or more of the following symptoms: anxiety, stress, insomnia or just plain blah (sound familiar?). None exercised regularly. We consulted clinical psychologists Smits and his Exercise for Mood and Anxiety coauthor, Michael Otto, Ph.D., then asked Laila Sarvarian, head trainer for Camp Gladiator in Dallas, to create a convenient six-week program for each woman, designed to target her mood problems. The outcome: Let’s just say the women used phrases like “life-changing.” (And “body-changing”—one woman lost 14 pounds!) Their “Rxercise” prescriptions can launch you into a happier life, too, whatever lies in wait for you today.

The science: “Exercise engages neurons in the brain, just like it engages muscles in the body. That raises the brain’s stress threshold,” Dr. Ratey says. “People who exercise regularly don’t respond as dramatically to stress as nonexercisers do. Their heart rate doesn’t shoot up as high, and their mood doesn’t sink as low.”

Schwerd’s hurdle: “I work long hours at a cancer center and have lots of meetings. That makes it hard to get to the gym,” Schwerd says. “I love my work, but it’s intense—I help patients deal with life-and-death issues. I want to enjoy my job without feeling exhausted by it.”

Newbie breakthrough: “On day 1, I took a killer conditioning class called Hard Core Cuts at Equinox. It was intimidating, but I felt connected to my body for the first time in a long time. The next morning, I actually woke up before my alarm and was like, ‘Hello, world!'”

Her week 2 breakthrough: “I fell in love with a class called Barre Burn, which incorporates pilates moves. All my energy used to go into my job. Once I started exercising, I could work during the day, go to the gym at night and still have energy to spare.”

Her key to calm: “When I’m on the elliptical, I put on my music and Zen out. My stress disappears.”

Six weeks later: “I’ve come so far from the girl who was cursing the day I agreed to this plan. I exercised for only four of the six days I was supposed to—my gym is by my office so it was easier to do it at lunch or after work than on weekends—but the program was life-changing. If I had 8 minutes, I’d get on the treadmill for 8 minutes. The more I exercised, the more in tune I got with myself. I moved to a new neighborhood I love and started going out to hear local bands again, which makes me happy. I’m no longer overwhelmed by work, and I fit into clothes that used to be too small. I’m hooked on the exhilaration of pushing myself physically.”

Why the mix works: “To build Heather’s confidence and make sure she didn’t get discouraged, I started with easy goals,” Sarvarian says. “We got her heart rate up with short spurts of machine exercise, then moved on to group classes or workouts with friends. Being accountable to someone will help her stay motivated.”

The science: Exercise is a powerful weapon against the blues. “In the short term, it can elevate mood when you’re feeling down. Long term, it can knock out milder forms of clinical depression,” Smits says. And as little as 60 minutes a week of any kind of physical activity (no arduous gym sessions necessary) can do it: Researchers at The University of Queensland School of Human Movement Studies find that subjects who did low-level activities for at least an hour a week cut their risk for depression by 30 to 40 percent.

Finn’s hurdle: “I gained 50 pounds in the last year partly because I’d been so low,” Finn says. “My cat Squirrel died, and I ate for comfort. The weight gain made me feel bad about my body—I was too embarrassed to exercise in front of anyone. Seeing myself in the mirror at the gym was disheartening.”

Her biggest motivator: “It really helped to have Larysa Didio train me. I wanted to please her, so I pushed myself and started losing weight right away, which made me feel better. I also loved walking with a friend by the Hudson River. There were tons of people biking or walking their dogs. I always felt happier afterward.”

Her week 3 breakthrough: “I started with 10- or 15-minute workouts, but even those gave me a sense of accomplishment. From there, I began building a fitness base, and by the third week, something clicked. I wasn’t exercising because I had to but because I wanted to. It helps me feel good all day, and I accomplish more.”

How exercise helped her in a crisis: “Toward the end of the program, my second cat, Shep, died. I felt incredibly lonely, but I kept working out, because I knew it would make me feel better. And it did. After six weeks of regular exercise, I was happier and felt more positive about my body. Plus, I lost 14 pounds! I can’t believe how much more confident I feel.”

Why the plan works: “Gabby puts in 60-hour weeks, so she has to get her exercise in early and make the most of it,” Sarvarian says. “She had been a runner in the past, so I thought it would be fun to help her train for a race. It’s motivating to have a goal.” Getting sunlight in the morning can also help reset Gabby’s biological clock so she’ll fall asleep more easily at night. And circuit training, as well as more relaxing options like yoga, will tire her out, so she can sleep longer and more soundly.

The science: In a 2010 study, researchers at Northwestern University put people with insomnia on a 16-week exercise program, starting with walking, riding a bike or jogging for 10 to 15 minutes at a time; by week six, they were doing 30 to 40 minutes, four times a week. Afterward, subjects reported a significant bump in the quality of their shut-eye—they fell asleep faster, slept more hours, experienced better moods and felt more alert during the day.

Rosenthal’s hurdle: “My plan called for exercising in the morning, but I’m a night owl,” Rosenthal says. “Waking up at 5:30 or 6 a.m. was brutal, especially at first. The alarm would go off and I’d think, Nooo!!!”

Her day 3 breakthrough: “On my third night, I had my first really great night’s sleep—I slept like a baby instead of waking up several times like I usually do. It was wonderful, especially when I had more energy during my morning run. The same thing happened on day 6—I slept for 11 hours! I tried to make a conscious effort to turn off the TV and go to bed earlier. Sleeping well helps me exercise harder, which helps my state of mind, which helps me sleep. Upward spiral!”

How she surprised herself: “During my third week, I had a big event to plan for, and I wasn’t able to exercise nearly as much. My sleep suffered, and my mood did, too. But that week ended on a high: I ran a 5K! I used to be a runner, but I hadn’t done it for a year before this program. My goal was to finish in 35 minutes, and I finished in 32!”

Six weeks later: “It used to be hard for me to fall asleep and stay asleep. In the morning, I’d have trouble waking up and I’d be groggy all day. Now I sleep more soundly. The harder I work out, the deeper I sleep. I don’t know if it’s the extra sleep, the endorphin boost or the pound or two of weight I’ve lost, but since starting the program, I feel more on my game, like I’ve got a bit of a swagger. I’m doing my thing—and feeling good about myself.”

Why the plan works: “Shakira has two kids, ages 3 and 5, so I gave her options that let her exercise with her family, like walking,” Sarvarian says. “Because she loves sports, we got her playing tennis once a week, which is a great cardio workout. And yoga will help her relax.”

The science: “Vigorous exercise may be key for people who have panic attacks,” Smits says. “You experience rapid heartbeat and heavy breathing—the same symptoms that occur in anxiety. But when you exercise, you can get accustomed to those symptoms and stop seeing them as negative.” In a study from the University of Georgia in Athens, sedentary women with generalized anxiety disorder started doing two 16-minute sessions of cardio a week. After six weeks, 40 percent no longer met the diagnostic criteria for the disorder. Yoga works, too. Researchers at Boston University School of Medicine find that yogis who practiced for an hour, three times a week for 12 weeks, had sharper dips in anxiety and felt calmer than a group who walked slowly for the same amount of time.

Johnson’s hurdle: “With two small children, it was tough to see how I could fit in all the exercise,” Johnson says. “In fact, I didn’t manage to do anything the first week. After that failure, I realized I’d have to schedule my workouts like I would a work appointment. So I took out my smartphone and the gym schedule and put classes and workout times into it. After that, I managed to get to the gym and to a tennis lesson at least four days a week for the rest of the program, as well as do other things, like take walks with my family.”

Her week 3 breakthrough: “At first, exercising made me feel tired, but after three weeks, when I got into better shape, I felt more energetic and had an easier time managing my anxiety—the workouts helped me reboot. And I discovered a hip-hop class I really love. When I’m doing it, I’m in the moment, not overwhelmed. I can let my stress go.”

How she lost inches—and anxiety: “I wasn’t aiming to lose weight, but I lost 4 pounds and 2 inches off my waist. Best of all, once I found a gym with child care and stopped beating myself up if I was a few minutes late to class, I really got into my workouts. Afterward, I felt calm—and sexier! Before I began exercising, I was having several anxiety attacks a week. But I only had two mild ones during the program.”

Six weeks later: “Exercising changed my attitude. It forced me to take time for myself and remember who I am: a strong, sexy, athletic woman. What a gift!”